Search Results (5,143)

Background/Objectives: Neglected tropical diseases (NTDs) caused by protozoan parasites such as Trypanosoma cruzi, Trypanosoma brucei, Leishmania spp., and Plasmodium falciparum remain a global health challenge due to limited therapies and increasing drug resistance. Natural products provide diverse scaffolds for antiparasitic drug discovery. This study aimed to investigate the multitarget inhibitory potential of alkaloids isolated from Croton linearis Jacq. against validated protozoan enzymes. Methods: Eighteen alkaloids were virtually screened against 17 molecular targets relevant to protozoan parasites. Protein–ligand docking simulations were performed using crystallographic structures of enzymes, including Cyp51, DHFR-TS, PTR1, AD-kinase, and DHODH. Predicted interactions were analyzed to identify hydrogen bonds, hydrophobic contacts, and π–π stacking with key residues in the active sites. Results: Several alkaloids exhibited high binding affinities, in some cases surpassing co-crystallized ligands. Reticuline, norsalutaridine, laudanosine, and jacularine consistently showed the strongest activity, with docking scores ranging from −8.0 to −9.3 kcal/mol across multiple targets. Notably, norsalutaridine displayed the highest predicted affinity for L. infantum Cyp51, while reticuline showed strong binding to T. cruzi DHFR-TS and L. major PTR1. Conclusions: The study highlights the potential of C. linearis alkaloids as multitarget inhibitors against protozoan parasites. These compounds represent promising lead candidates for the development of antiparasitic agents, while emphasizing the value of natural product scaffolds for neglected disease drug discovery. The findings also support the future exploration of semisynthetic derivatives to optimize activity and selectivity. Full article

The objective of this work was to evaluate the antidiabetes potential of protein hydrolysates derived from “vaina morada” black bean (Phaseolus vulgaris L.). Bioactive peptide sequences were identified after in silico digestion. The biological activities and molecular interactions of peptides with targeted enzymes were assayed. The degree of hydrolysis and protein profile were evaluated throughout the processing stages, including protein extraction, hydrolysis, and dialysis. Biological potential assays, including antioxidant potential (DPPH and ABTS•+), and inhibition of α-amylase and α-glucosidase enzymes, were performed. Identified bioactive peptides showed potential for inhibiting ACE and DPP-IV, as well as exhibiting antioxidant potential. Molecular docking indicated that several peptide sequences showed equal or stronger binding affinities compared to acarbose. Notably, sequence VNDNGEPTL exhibited binding energies of −10.0 kcal/mol (α-amylase) and −11.8 kcal/mol (α-glucosidase). Protein hydrolysates showed the lowest IC₅₀ (113.16 µM TE/mg for ABTS•+), while dialyzed protein hydrolysates demonstrated the strongest activity for DPPH (IC₂₅ of 38.83 µM TE/mg). Also, the dialyzed hydrolysate demonstrated the highest enzyme inhibition, with IC₅₀ values of 0.78 mg/mL for α-amylase and 0.60 mg/mL for α-glucosidase. “Vaina morada” black bean protein hydrolysates are a rich source of multifunctional peptides, supporting their potential application in functional food formulations aimed at preventing or managing type 2 diabetes. Full article

Colon cancer (CC) is a common malignancy characterized by poor prognostic outcomes and considerable mortality. Oxaliplatin (OXP) is commonly used in the treatment of CC; however, its efficacy may be limited by side effects and the development of resistance. β-sitosterol (β-Sit), a phytosterol derived from plants, has been documented to be effective in the treatment of tumors. This study aimed to investigate the potential of β-Sit to enhance the antitumor efficacy of OXP in COLO-205 cells, focusing on apoptosis induction and suppression of the vascular endothelial growth factor A (VEGF-A)/survival pathway. Molecular docking studies were performed to assess the binding affinity of β-Sit with the target proteins B-cell lymphoma 2 (Bcl-2), phosphoinositide 3-kinase (PI3K), and VEGF receptor-2 (VEGFR-2). COLO-205 cells were treated with OXP, β-Sit, or a combination of OXP + β-Sit for 48 h. The combination treatment substantially lowered the IC₅₀ achieved with 3.24 µM of OXP and 36.01 µM of β-Sit, compared to 25.64 µM for OXP alone and 275.9 µM for β-Sit alone, demonstrating a pronounced synergistic impact. The combined therapy altered the cell cycle distribution by decreasing the number of cells in the G0/G, S, and G2/M phases, coupled with an increase in the Sub-G1 population. Furthermore, apoptosis was augmented by a shift in cell death from necrosis to late apoptosis, as indicated by an increased BAX/BCL2 ratio relative to each treatment alone. Moreover, the inhibitory effect on angiogenesis was enhanced via the reduction of VEGF-A, and β-catenin and nuclear factor κB (NF-κB-p65) were suppressed, thereby preventing the growth and survival of resistant cancer cells. Additionally, molecular docking supported high binding affinities of β-Sit to Bcl-2, PI3K, and VEGFR-2. This study highlights the potential of β-Sit to enhance the anti-cancer efficacy of OXP in CC. Full article

This study theoretically explores the mechanism of action of Chicoric acid against influenza virus based on network pharmacology, molecular docking, and molecular dynamics simulation techniques, aiming to provide insights for the development of new veterinary drugs for influenza. Potential targets for influenza virus action were identified using the PharmMapper (i.e. Version 2017) server and disease databases including GeneCards and OMIM. The STRING online analysis platform and Cytoscape 3.9.1 software were employed to construct a protein–protein interaction (PPI) network of the target proteins, followed by topological analysis to screen for key targets. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed on the intersecting targets using the DAVID database. A “drug–target–pathway” network diagram was constructed using Cytoscape 3.9.1 software. Molecular docking was carried out with AutoDock 1.5.6 and PyMOL 2.5 software to identify dominant binding targets, followed by molecular dynamics simulation analysis. The results of network analysis showed that there were 31 potential targets of Chicoric acid; the protein interaction network suggested that UBC, UBA52, RPS27A, HCK, and CDKN1B may be the core targets of Chicoric acid; 55 cell biological processes were obtained by GO enrichment analysis, and 15 related signaling pathways were obtained by KEGG pathway enrichment analysis; molecular docking showed that UBC and UBA52 had a good affinity to Chicoric acid and may be the dominant target of Chicoric acid exerting its effect. Chicoric acid may play a role in antiviral activity by acting on the dominant protein of UBC and UBA52, thus achieving an anti-influenza virus effect. Full article

Background: Ewing sarcoma (ES) is a rare tumor that affects children, adolescents, and young adults. ES is associated with high morbidity in all patients and high mortality for those who present with metastatic disease. A chromosomal translocation, either t(11;22)(q24;p12) or t(21;22)(q22;q12) leads to the fusion oncoproteins EWS::FLI1 or EWS::ERG in 95% of ES patients. We recognized a critical need for a stably sourced high-affinity antibody that recognizes EWS::FLI1 with maximal specificity. Understanding EWS::FLI1 protein complexes is a pivotal gap in ES knowledge that necessitates the development of antibodies capable of identifying native proteins in solution. Further, variable epitope sequencing of a monoclonal antibody enables the construction of degraders and nanobody identifiers. Methods: Monoclonal antibodies were produced following informed peptide synthesis, injection, and hybridoma creation. Hybridoma antibodies were validated for specificity and function. Results: Our results indicate that the FLI1 1.2 monoclonal antibody, which recognizes the EWS::FLI1 fusion oncoprotein, can be reliably applied to multiple molecular biology applications like immunoblot, immunoprecipitation, immunofluorescence, and immunohistochemistry. This FLI1 1.2 monoclonal antibody has a high affinity of 0.3 nM KD to EWS::FLI1. In terms of specificity, this antibody is highly specific to EWS::FLI1 and some cross reactivity with ERG. Conclusions: This reagent will provide the research community with valuable tools for further biochemical and genomic interrogation of the oncogenic activity of EWS::FLI1 in ES. Full article

Bovine parainfluenza virus type 3 (BPIV3) is a significant pathogen implicated in bovine respiratory disease complex (BRDC), leading to lung tissue destruction, immunosuppression, and subsequent bacterial infections in cattle, hence incurring considerable economic losses globally. Notwithstanding its importance, a limited number of commercial vaccinations are presently accessible. The fusion (F) protein and hemagglutinin-neuraminidase (HN) protein, as protective antigens of the Paramyxoviridae family, can elicit neutralizing antibodies and are regarded as optimal candidates for the creation of genetically modified vaccines. A multi-epitope-based peptide vaccine (MEBPV) was developed by immunoinformatics methodologies by choosing epitopes from the F and HN proteins characterized by high antigenicity, moderate toxicity, and limited allergenic potential. The epitopes were combined with suitable linkers and adjuvants to produce the vaccine, whose physicochemical qualities, immunological attributes, solubility, and structural stability were improved and evaluated using computational methods. Molecular docking and molecular dynamics simulations demonstrated the strong potential binding affinity and stability of the vaccination with TLR2, TLR3, and especially TLR4 receptors. Immune simulations forecasted strong humoral and cellular responses, accompanied by a significant elevation in interferon-γ (IFN-γ) production. The vaccine sequence was later cloned into the pET-28a (+) vector for possible expression in Escherichia coli. Despite in silico predictions suggesting a favorable immunogenic potential, additional in vitro and in vivo studies are necessary to confirm its protective efficacy and safety. This research establishes a solid foundation for the creation of safe and efficacious subunit vaccines targeting BPIV3 and presents novel perspectives for the formulation of vaccinations against additional viral infections. Full article

The changes in charge distribution caused by mutations in the spike protein may play a crucial role in balancing infectivity and immune evasion during the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To explore how charge increments in spike protein variants influence viral evolution, a statistical analysis was conducted on 57 SARS-CoV-2 variants, examining relationships between charge distribution, lineage divergence, angiotensin-converting enzyme 2 (ACE2) affinity, immune evasion, and receptor-binding domain (RBD) expression. A phylogenetic tree was also reconstructed using only the charge properties of mutation sites. Results indicated that with increasing lineage divergence, overall positive charge initially rose sharply and then more gradually. Partitioning the spike protein into three domains—the RBD, the N-terminal flanking region (B-RBD), and the C-terminal flanking region (A-RBD)—revealed distinct patterns: positive charge increased in the RBD and A-RBD, whereas the B-RBD accumulated negative charge. Charge increments were negatively associated with ACE2 affinity and RBD expression but positively correlated with immune evasion. The k-mer-based tree derived from charge-reduced sequences showed a topology consistent with the whole-genome tree. These findings suggest that charge distribution in spike proteins is closely linked to viral evolution, with the opposing trends in the RBD and B-RBD potentially reflecting a balance between infectivity and immune escape. Full article

Background: Human insulin-like growth factor 1 (hIGF-1) plays a key role in cell proliferation and tissue repair. While plant expression systems offer a cost-effective and scalable alternative for recombinant protein production, the molecular effects of plant-derived hIGF-1 on mammalian cells remain largely unexplored. Methods: In this study, a recombinant fusion protein of hIGF-1 with human Fc (hIGF-1-Fc) was transiently expressed in Nicotiana benthamiana using the geminiviral pBYR2e system and purified by Protein A affinity chromatography. SDS-PAGE and Western blotting confirmed the predicted molecular weight, and LC-MS identified N-glycosylation at the Fc N229 site with plant-type glycans such as GnMXF, GnGnXF, and MMXF. Bioactivity was evaluated using MCF-7 cell proliferation and NIH3T3 wound healing assays. Label-free quantitative proteomics was performed on NIH3T3 fibroblasts to assess molecular changes. Results: hIGF-1 Fc significantly promoted cancer cell migration and fibroblast proliferation. Proteomic profiling revealed an abundance of cytoskeletal proteins such as actin and tubulin and metabolic enzymes related to energy production. Gene ontology and pathway enrichment analyses indicated significant modulation of ribosome biogenesis and carbon metabolism. Conclusions: This study presents the first proteome-level investigation of plant-produced hIGF-1-Fc in mouse fibroblasts and reveals its impact on cytoskeletal organization and metabolic pathways involved in proliferation and wound healing. Full article

Background/Objective: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) lacking targeted therapies and characterized by high tumor heterogeneity. In this study, we evaluated the anticancer activity and mechanistic profile of Simalikalactone D (SKD), a quassinoid compound derived from the endemic Puerto Rican tree Simarouba tulae, in three TNBC cell lines, MDA-MB-468, MDA-MB-231, and SUM-149. Methods: MDA-MB-468, MDA-MB-231 and SUM-149 TNBC cells were evaluated for cell viability, proliferation and migration following SKD treatment. Phospho-antibody array, proteomics, and Western blot analyses were used to explore the SKD mechanism of action in MDA-MB-468 and MDA-MB-231 cell lines. Molecular docking was performed to assess SKD’s interaction with potential intracellular targets. Results: SKD exerted a concentration-dependent effect on the three cell lines. However, MDA-MB-468 cells exhibited an IC₅₀ of 67 nM, while the IC₅₀ values for MDA-MB-231 and SUM-149 were 422 nM and 598 nM, respectively. In MDA-MB-468 cells, 100 nM of SKD induced apoptosis, evidenced by the activated caspase-3 activity, PARP-1 cleavage and decrease in Bcl-2 and survivin protein levels. Sublethal SKD (25 nM) impaired migration in MDA-MB-231 cells and reduced proliferation and motility in SUM149 cells. A 6 h SKD treatment markedly reduced phosphorylation of apoptosis-related proteins (p53, BAD, DAXX, AKT1, JUN) and Jak/STAT pathway components, indicating early disruption of intracellular signaling prior to phenotypic changes. Proteomic profiling showed distinct pathway alterations in both MDA-MB-468 and MDA-MB-231 cells, with reduced Integrin β1 (ITGB1) levels emerging as a shared effector. This suggests that SKD broadly disrupts cell adhesion and migration independently of apoptosis-driven cell death. Western blot validation confirmed reduced ITGB1 protein levels across all three TNBC cell lines examined. In silico docking confirmed favorable binding affinities of SKD to both EGFR (ΔG = −6.718 kcal/mol) and STAT4 (ΔG = −8.481 kcal/mol). Conclusions: Overall, our findings suggest that SKD is a potent anticancer agent in a subgroup of TNBC cells. Full article

Despite their ecological importance and unique evolutionary history, reptiles remain underrepresented in immunological research. The innate immunity of the cottonmouth (Agkistrodon piscivorus), a semi-aquatic pit viper native to the southeastern United States, was characterized to provide insight into the molecular and cellular mechanisms underlying its first line of defense against pathogens. Plasma collected from wild A. piscivorus exhibited strong antibacterial activities against both Gram-negative and Gram-positive bacteria. In addition, plasma from A. piscivorus showed potent hemolytic activities in unsensitized sheep red blood cell (SRBC) hemolysis assays. This activity was concentration-, time-, and temperature-dependent. In addition, the hemolytic activity was inhibited by mild heat treatment (56 °C, 30 min) of plasma and proteases and also by EDTA, suggesting that the hemolytic activity was due to the presence of serum complement proteins. SDS-PAGE analysis of plasma proteins isolated from a mannan-agarose affinity column revealed the presence of a protein with a mass of 36 kDa, raising the strong possibility that the lectin pathway of complement activation is active. The EC₅₀ for hemolysis of SRBCs by plasma from A. piscivorus was approximately 10–100× lower than that of any other reptilian species described. This is the first study to characterize innate immunity in A. piscivorus. Full article

Over the past few decades, Fc fragment-conjugated proteins, such as Protein A, have been extensively utilized across a range of applications, including antibody purification, site-specific immobilization of antibodies, and the development of biosensing platforms. In this study, building upon our group prior research, we designed and screened an affinity DNA functional ligand (A-DNAFL) and experimentally validated its binding affinity (K_D = 6.59 × 10⁻⁸) toward mouse IgG antibodies, whose binding performance was comparable to that of protein A. Systematic evaluations were performed to assess the binding efficiency under varying pH levels and ionic strength conditions. Optimal antibody immobilization was achieved in PBST-B buffer under physiological pH 7.2–7.4 and containing approximately 154 mM Na⁺ and 4 mM K⁺. Two competitive binding assays confirmed that the A-DNAFL binds to the Fc fragment of murine IgG antibody. Furthermore, molecular docking simulations were employed to investigate the interaction mode, revealing key residues involved in binding as well as the contributions of hydrogen bonding and hydrophobic interactions to complex stabilization. Leveraging these insights, A-DNAFL was utilized as a tool for oriented immobilization of antibodies on the sensing interface, enabling the construction of an immunosensor for ricin detection. Following optimization of immobilization parameters, the biosensor exhibited a detection limit of 30.5 ng/mL with the linear regression equation is lg(Response) = 0.329 lg(C_ricin) − 2.027 (N = 9, R = 0.938, p < 0.001)—representing a 64-fold improvement compared to conventional protein A-based methods. The system demonstrated robust resistance to nonspecific interference. Sensing interface reusability was also evaluated, showing only 8.55% signal reduction after two regeneration cycles, indicating that glycine effectively elutes bound antibodies while preserving sensor activity. In summary, the A-DNAFL presented in this study represents a novel antibody-directed immobilization material that serves as a promising alternative to protein A. It offers several advantages, including high modifiability, low production cost, and a relatively small molecular weight. These features collectively contribute to its broad application potential in biosensing, antibody purification, and other areas of life science research. Full article

Background: Despite extensive phytochemical research on white tea varieties, flavonoid profiling in Baihao Yinzhen remains scarce. The development of green and efficient extraction methods is essential to facilitate its potential application in cosmetic formulations. Methods: A deep eutectic solvent-based ultrasound-assisted extraction (DES-UAE) was developed for Baihao Yinzhen flavonoids. After screening of 14 DESs and optimizing the conditions via single-factor and response surface methodology, the extracts were analyzed by UPLC-MS. Anti-inflammatory activity was assessed in LPS-induced RAW264.7 cells by measuring TNF-α and IL-6 levels, with molecular docking simulating flavonoid–cytokine interactions; Results: Among 14 tested deep eutectic solvents, hydroxypropyl-β-cyclodextrin/lactic acid (HP-β-CD/La) was identified as the most effective solvent for flavonoid extraction. Under optimized conditions (HBD/HBA mass ratio 3:1, temperature 60 °C, water content 40%, solid–liquid ratio 1:19, extraction time 62 min), the maximum flavonoid yield reached 108.72 mg RE/g DW. The DES extract (2.5 μg/mL) significantly suppressed TNF-α and IL-6 secretion in LPS-stimulated RAW264.7 cells compared to the water extract. UPLC-MS identified five major flavonoid glycosides, and molecular docking revealed their strong binding affinities with TNF-α and IL-6 proteins. Conclusions: DES-UAE provides an efficient green method for flavonoid extraction. The extract demonstrates significant anti-inflammatory activity, supporting its potential as a natural cosmetic ingredient. This study aimed to develop an efficient and green DES-UAE method for the extraction of flavonoids from Baihao Yinzhen, in order to evaluate the antioxidant and anti-inflammatory activities of the extract and to explore the potential interaction mechanisms of key flavonoids with inflammatory targets via molecular docking. Full article

Several pieces of evidence have demonstrated the sigma-1 receptor (S1R) as a druggable protein with important therapeutic potentials, including neurodegeneration, cancer, and neuropathic pain. The density of S1R is altered in pathological processes so that its imaging is under study for diagnostic purposes. Thus, research has been focused on the development of S1R positron emission tomography (PET) radioligands, not only as diagnostic tools but also as powerful means to assist in the drug-development process. Herein, we comprehensively review the most important S1R PET radiotracers belonging to different classes that have been developed in the last two decades. Starting from the structural modifications impacting on the S1R affinity and selectivity, we report (i) the differences in metabolism and pharmacokinetics, (ii) the in vivo behavior in different animal models, (iii) the in vitro autoradiography outcomes, and (iv) the dosimetric profiles. The successful use of the best-performing S1R PET radiotracers in the characterization of novel S1R drugs is also reported together with the approaches to assess the potential for clinical translation. What emerges from this review is that, although the development of reliable PET agents appears to be extremely challenging, these radiotracers hold incredible potential and play a fundamental role in the exploitation of S1R in health and disease. Full article

Akkermansia muciniphila (AKK) is a mucin-degrading gut symbiont with emerging probiotic potential. Among its carbohydrate-active enzymes, Amuc_0517, a glycoside hydrolase family 36 (GH36) protein, has been identified as a highly specific α-galactosidase. In this study, the Amuc_0517 gene was cloned into pET-28a(+), expressed in Escherichia coli BL21, and purified via Ni²⁺-NTA affinity chromatography. Bioinformatic analysis indicated the presence of a signal peptide and α-galactosidase domain. Enzyme assays confirmed its ability to cleave α-1,6-glycosidic bonds in pNPGal, with no detectable activity toward pNPGlu, and molecular dynamics simulations revealed stronger binding affinity and lower free energy with pNPGal, supporting its substrate specificity. Given that α-galactosidases are widely applied in the dairy industry to hydrolyze galactose-containing oligosaccharides in milk and whey, the biochemical features of Amuc_0517 suggest its potential as a novel biocatalyst for functional dairy processing and probiotic-enriched dairy product development. Full article

Affibody molecules have emerged as versatile protein engineering platforms due to their exceptional binding properties. These small (6.5 kDa) three-helix bundle proteins, derived from the Z-domain of Staphylococcal protein A, can be engineered to bind diverse molecular targets with high affinity and specificity. This structural and functional versatility has driven their applications in diagnostics, therapeutics, and biosensing. This review examines the evolution from monomeric affibody constructs to multivalent supramolecular assemblies, highlighting how this shift overcomes key limitations while expanding functionality. Recent advances in conjugation chemistry, scaffold engineering, and protein design have enabled sophisticated affibody-based architectures with enhanced pharmacokinetic profiles and multivalent binding capabilities, thereby improving their utility in targeted drug delivery, molecular imaging, and theranostics. Full article